1. Field of the Invention
The present invention relates to an apparatus for recording and/or reproducing an information with a plurality of heads arranged on a rotary drum.
2. Description of the Prior Art
In a video tape recorder (hereinafter simply referred to as VTR) of 1 (or 1.5) rotary head type using a magnetic tape of 1-inch wide, that is, a VTR using a so-called SMPTE type C format, two rotary heads are mounted on a rotary drum, this rotary drum is rotated at a revolution rate of one rotation per one field and a magnetic tape is obliquely wrapped around the peripheral surface of this rotary drum at an angle of substantially 360 degrees and transported at a predetermined speed. Of the above mentioned two rotary heads, the video signal is recorded by one rotary head during its video period, while a vertical synchronizing signal is recorded by another auxiliary head during the synchronizing period in which the former rotary head is detached from the magnetic tape.
By the way, in such a format, if a reproduced signal is processed by a so-called time base corrector, even when the signal in the synchronizing period is dropped, the normal video signal can be reproduced without problem if the signal in the video period is obtained. Therefore, it may be considered that in the above mentioned format, instead of the signal in the synchronizing period, a digital PCM (pulse-code-modulated) audio signal be recorded on a skewed track which is narrow in width.
Specifically, according to the prior art format as mentioned above, the audio signal is recorded in the form of an analog signal by a stationary or fixed head. In such an analog recording, if especially the dubbing of such a recorded analog audio signal is carried out repeatedly, the analog audio signal is deteriorated considerably. On the other hand, if the audio signal is recorded in the form of a digital signal, it is possible to remove the problem that the audio signal is deteriorated in the dubbing operation.
The above mentioned system is disclosed, for example, in Japanese Laid Open Patent Application No. 57-119571.
However, in order that an audio data of one field period is recorded in the synchronizing signal track, the digital data must be time-base-compressed considerably and this makes the signal processing very difficult. In addition, the recording density (or packing density) becomes large so that the above mentioned system is difficult to be realized in the recording and/or reproducing system.